Internal combustion engine



April 21, 1936. D G. ROOS INTERNAL COMBUSTION ENGINE Filed Dec. l0, 1932 5 Sheets-Sheet l INVENTOR. B y M April 21, 1936., D. G. 'Roos v INTERNAL COMBUSTION ENGINE v Filed Dec. l0, 1932 5 SheecS-Sheet 2 iN VENTOR. m

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Patented Apr. 2l, 1936 iJNiTED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Delmar G. Roos, South Bend, The Studebaker Corporation,

Ind., assignor to South Bend, Ind.,

10 Claims.

This invention is a continuation in part of my application, Serial No. 568,968 filed October 15, 1931, and relates to improvements in internal combustion engines and particularly to an internal combustion engine having ten cylinders in line, and has for its principal object the provision of an in-line ten cylinder internal combustion engine which will develop the maximum horse power, and at the same time be smooth and quiet in operation.

A more specic object lies in the provision in an engine of the character described, of a system of manifolding a crank shaft and a timing arrangement which will be conducive to improved engine performance in matters of. power output, fuel economy, smoothness of operation and durability of the engine.

A further object resides in the provision of an intake manifold by means of which each cylinder will be fed directly from a central distributing chamber and there will be no tendency for one cylinder to obtain a greater or less charge of explosive mixture than any other cylinder.

A still further object lies in the provision of a crank shaft so arranged that the inertia forces of. the moving parts of the engine are balanced and one force will cancel out another force to provide smooth and quiet engine operation and reduce the stresses on the bearings and moving parts of the engine.

An additionalobject resides in the provision y of a firing order which will so distribute the power loads upon the crank shaft as to minimize the torsional vibration in the crank shaft and at the same time will distribute the operating forces of the engine about the center of gravity thereof in such a manner that there will be no tendency for the engine to rock in either direction about its center of gravity.

Another object lies in the provision of an internal combustion engine of the character described which will be economical to manufacture, easy to operate and durable in use.

Other objects and advantages of. the invention will appear as the description proceeds.

The accompanying drawings illustrate an acceptable mechanical embodiment of the idea of the invention. The drawings, however, are to be taken as illustrative only and not as limiting the invention, the scope of which is to be measured entirely by the scope of the sub-joined claims.

1n the drawings:

Figure 1 is a top plan view of an internal combustion engine constructed according to the idea (Cl. 12S-52) of this invention, showing my improved intake manifold applied thereto.

Figure 2 is a vertical side elevation of the upper portion of an internal combustion engine showing intake and exhaust manifolds construct- 5 ed according to the idea of this invention applied theretof Figure 3 is a vertical elevational View similar to Figure 2 showing a sectional View of the intake manifold taken on the line 3-3 of Figure 1.

Figure 4 is a sectional view through one element of the intake manifold and a portion of the cylinder block of the engine taken on the line 4-4 of. Figure 2.

Figure 5 is a sectional View of the intake manifold taken on the line 5-5 of Figure 1 looking in the direction of the arrows.

Figure 6 is a vertical sectional view of the intake and exhaust manifolds in assembled relation taken on the line 6 6 of Figure 1.

Figure 7 is a vertical side elevational view of an internal combustion engine constructed according tothe idea of this invention, a portion thereof being broken away to better illustrate the construction thereof.

Figure 8 is a longitudinal elevational view of a crank shaft forming an integral part of the internal combustion engine of this invention.

Figure 9 is a front end View of the crank shaft illustrated in Figure 8.

Figure 10 is a sectional view of the crank shaft illustrated in Figure 8 taken on the line lll- I0 of Figure 8 looking in the direction of the arrows.

Figure 11 is a sectional View of the crank shaft illustrated in Figure 8 taken on the line II-l I of Figure 8 looking in the direction of the arrows.

Figure 12 is an additional sectional View of the crank shaft illustrated in Figure 8 taken on the line i12-I2 of Figure 8 looking in the direction of the arrows. y

Figure 13 is a schematic illustration of the crank shaft showing the method of counterbalancing the same.

Figure 14 is a schematic View of, the engine showing the manner in which the inertia forces are opposed to each other and distributed about the center of gravity of the engine.

Referring to thedrawings in detail and particularly to Figure 1, it will be observed that I have provided an internal combustion engine of ten cylinders in line as indicated by the spark plugs l. At the rear end thereof the engine is provided with a flywheel l2 which may be of conventional construction and carry gear teeth I3 which comprise a part of the self-starting mecha- 55 nism. At the forward end thereof the engine is provided with a vibration dampener |4, a fan belt pulley I5, and a timing gear casing I6, the vibration dampener and fan belt pulley being secured to the engine by means of a starting crank nut 8. The top of the engine as illustrated in Figure l is covered by a cylinder head formed in tvvo parts, 2|? and 2|, secured to the engine cylinder block by means of the hold-down bolts 22. A cooling water conduit 24 extends along the top of the engine above the cylinder heads 25 and 2| and is operatively connected to the cylinder heads 20 and 2| by means of the flanged fixtures 26 and 21 respectively. An exhaust manifold 28 extends along one side of the engine and an intake manifold generally indicated at 35 extends along the same side of the engine in assembled relation with the exhaust manifold 28.

From an inspection of Figure 2, it will be observed that the exhaust manifold 28 and intake manifold 30 are secured together by means of stud bolts 33 and that the assembled manifolds are .secured to the engine by means of stud bolts 34 and cooperating hanged portions 35 and 36 on the exhaust and intake manifolds respectively.

Referring again to Figure 1 it will be observed that the exhaust manifold 28 is formed in three parts as indicated at 31, 38 and 39, the end portions 31 and 39 being telescopically united with the center portion 38 as indicated at 4E) and 4|. The intake manifold 3G is also formed in three separate parts as indicated at 43, 44 and 45, the end portions 43 and 45 being secured to the center portion 44 by means of the stud bolts 46 illustrated in Figure 2, gaskets 48 being interposed between the adjacent surfaces of the members 43 and 45 and the member 44 to provide a gas-tight seal therebetween. A chamber 59 is formed on the center portion 38 of the exhaust manifold and underlies a chamber 5| formed in the center portion 44 of the intake manifold. An apertured plate v52 is inserted between the adjacent surfaces of the chambers 55 and 5| and gaskets 53 Aand 54 are disposed, one upon either side of the plate 52 between the plate and the adjacent surfaces of the chambers 50 and 5| respectively to form a gas-tight seal between the chambers 50 and 5|, and, as explained above, the chambers 5D and 5| are rigidly secured together by means of the stud bolts 33. In the form of the invention illustrated, a down-draft carburetor generally indicated at 55 is mounted upon the top surface of the chamber 5|. The invention, however, is not specifically limited to the carburetor as shown nor to a downdraft carburetor, as an up-draft carburetor may be used upon slight modification of the construction of the chambers 5E and 5|. The carburetor illustrated is provided with a throttle valve 51, a Venturi chamber 58, a float bowl 5S and a choke valve 65. An automatic choke control device generally indicated at 62 and including a thermostat is mounted upon the intake manifold and may be operatively connected with the choke valve 65 by means of linkage, not illustrated, for the purpose cf automatically controlling the choke valve in accordance with the operating temperature of the engine. A heating pad S4 is mounted upon the exhaust manifold and positioned in heat exchanging relation with the thermostat 63.

Attention is now directed to Figures 3, 4 and 5 for a more detailed description of the intake manifold. As illustrated in section in Figure 3, the center portion, or bar, 44 of the intake manifold, comprises a hollow member having two o-ppositely extending curved channels 55 and 55 leading from the top of the chamber 5| to the centers of the members 43 and 45 respectively. These are the channels through which the eX- plosive mixture is drawn from the carburetor 55 to the manifold portions 43 and 45 for distribution therethrough to the individual cylinders. In addition to the channels 65 and 66, the bar 44 is provided upon each side thereof with additional channels as indicated at E58 and 63 in Figure 5, and at 59 and 10 in Figure 3. These additional channels extend along the channels 65 and 65 upon each side thereof and lead from the interior of the chamber 5| to the interiors of the heating chambers 13 and 14 formed in the manifold portions 43 and 45 respectively at the centers thereof. In all, there are four' such additional passages extending along each side of each of the intake passages 65 and 65 from the interior of the chamber 5| to the interiors of the heating chambers 13 and 14 separated at their outer ends by partitions 15 and 16 respectively and these passages provide outlet and return channels for exhaust gases led from the chamber 5| to the heating chambers 13 and 14 to heat the intake charge before it is drawn into the cylinders. Each of the heating chambers 13 and 14 is provided interiorly thereof with a distributing chamber as indicated at 11 and 13 respectively in open communication with the intake channels 65 and 36, and with the interiors of the manifold portions 43 and 45 respectively. Each distributing chamber lies at the junction of the branches of the manifold portion in which it is located and is provided with a bottom wall 19 and a top wall provided with suitable apertures for the passage of intake and exhaust gases there.- through. Annularly spaced ports indicated at S2, 83, 84, 85 and 85 located between the adjoining branches of the manifold portion extend from below the bottom wall to the apertures provided in the tcp wall. .A space 88 is provided between the bottom wall of each distributing chamber and the bottom of the outer wall 39 of the containing heating chamber.

Referring to Figures 1 and 5, it `will be observed that the heating chambers 13 and 14 are substantially circular bowl-shaped castings, and that these bowl-shaped heating chambers are covered by substantially bowl-shaped portions formed on the ends of the bar 44 to provide a substantially spherical distributing and heating chamber at each end of the bar 44 and at the center of each of the manifold members 43 and 45. In the end of the intake manifold illustrated in Figures 4 and 5, the passages are so arranged that the exhaust gases iiow to the heating chamber 14 through the channel 69 and return to the chamber 5| through the channel 68. Referring to Figure 4, it will be observed that two of the ports, namely 82 and 83, lie upon one side of the intake channel 68 under the heating channel E59 and as the other three, namely 84, 85 and 83, lie upon the opposite side of the intake channel 56 and under the heating channel S8, the heating gases will flow into the heating chamber through the ports 82 and 83, circulate beneath the distributing chambers 18 through the space indicated at 88 in Figure 5, and out through the ports 84, 85 and 83 and the return channel 68. As illustrated in Figure 5, a bore has been provided leading from the bottom of the distributing chamber through a circular well 9| to the exterior of the heating chamber at the bottom thereof, and this bore is normally closed by a screw plug 92 which may be removed to drain condensed gasoline from the intake manifold if necessary. As

illustrated in Figure 4, each of the branches 93, 94, 95, 96 and 91 lead directly from the distributing chamber 18 to one of the engine intake ports. As illustrated in Figure 7, each of the intake ports as indicated by I is separate, that is, there are no Siamesed intake ports in this engine. This construction gives a direct and short intake passage from each intake port to the distributing chamber, thereby obviating the possibility of one cylinder starving an adjacent cylinder due to overlapping intake periods.

A further advantage of this construction resides in the fact that with the ring sequence which forms an integral part of this invention, namely a firing sequence in the order 1, '7, 2, 6, 3, 10, 4, 9 5, 8, or the reverse, 1, 8, 5, 9, 4, 10, 3, 6, 2, 7, the suction impulses through the branches 93, 94, 95, 96 and 91 occur in a sequence in the nature of a regular and recurring rotation about the distribution chamber 19. This rotational effect tends to give a whirling motion to the mixture in the distributing chamber and obviates the possibility of pocketing or stagnation with consequent condensation of gasoline, and insures an adequate supply of properly evaporated fuel to all of the cylinders at all times. As indicated in Figure it will be observed that the intake ports, one of which is indicated at 98, are short and direct and lead directly into the combustion chamber of the engine as indicated at 99. The particular engine illustrated is of the L-head type and the section illustrated in Figure 5 shows an intake valve |99 having a stem extending through the intake port 99 and a head at the junction of the intake port with the combustion chamber. It is to be understood, however, that the invention is not specifically limited to an L-head engine as illustrated and that the idea may with equal facility be applied to a valve-in-head or sleevevalve engine or other equivalent forms of internal combustion engines.

The section illustrated in Figure 6 shows the construction of the interiors of the chambers 59 and 5| and the manner in which the exhaust gas is diverted from the exhaust manifold into the heating chambers when it is desirable to heat the intake charge. As illustrated the chamber 59 formed on the central portion 38 of the exhaust manifold comprises a substantially Y- shaped member having a branch |9| in open communication with the exhaust manifold, a second branch |92 opening into the bottom of the chamber 5| formed in the intake manifold, a partition |93 between the two branches and an outlet portion |95 extending downwardly from the junction of the branches |9| and |92 and provided at its lower end with an apertured flange |96 for the attachment thereto of an exhaust conduit, not illustrated. A shaft |98 extends transversely through the chamber 59 at approximately the center thereof and is rotatably mounted in the chamber walls. A valve member |99 having a curved lower end ||9 is secured at approximately its center to the shaft |98 as by screws, one of which is indicated at Referring now to Figure 2 it will be observed that one end of the shaft |98 extends outwardly of the chamber and has attached thereto a weighted arm H3 controlled by a thermostat ||4. The construction of this portion of the device is fully illustrated and described in application, Serial No. 632,118 by Stanwood W. Sparrow for Heat control valve, filed September 8, 1932, now Patent No. 1,986,542, and it is believed that a further description is not essential to the disclosure of the present invention. A partition ||6 is provided in the upper portion of the branch |92 and forms a continuation of the valve |99 when the valve is in the operative position illustrated in Figure 6. This partition ||6 is continued in the chamber 5| as illustrated at ||1 and is also provided in the chamber 5| with a branch indicated at ||8 extending at an angle from the partition toward the outer wall of the chamber 5|. From the structure so far described it will be observed that when the valve |99 is in the position indicated in Figure 6 exhaust gases entering the branch |9| from the exhaust manifold 38 will be diverted upwardly through the portion of the branch |92 between the partition H6 and the partition |93 into the chamber 5|. By reason of the partition ||1, the exhaust gases will then be diverted into the channels 69 and 19 from which they will flow through the heating chambers 13 and 14 illustrated in Figure 3, and return from the heating chambers through the channel 68 and the fourth channel, not illustrated, to the opposite half of the chamber 5|. From this half of the chamber 5|, the exhaust gases will flow around the outer end of the partition |8 and into that portion of the branch |92 opposite the partition ||6 from the partition |93, and from this portion of the branch |92 through the outlet |95 into the exhaust conduit. An aperture |29 is provided in the outer wall of the chamber 5| opposite the outer end of the partition ||8 and this aperture is covered by a plate |2| provided with a semi-cylindrical extrusion as indicated at |22. The plate is secured to the wall of the chamber 5| by means of the screws |24 or other equivalent securing means and a gasket |25 is interposed between the adjacent surfaces of the plate and the chamber 5| to provide a gas-tight seal between the plate and the chamber. A shaft |21 is rigidly mounted in the plate |2| along the axis of the semicylindrical extrusion |22 and carries a coiled thermostat |28, the free end of which is operatively connected with a valve member |39 having` a curved lower end |3|. The valve |39 is positioned between the outer end of the partition ||8 and the adjacent inner surface of the plate |2| and is rotatably mounted upon the shaft |21 by means of apertured ears, one of which is indicated at |32. As the temperature of thermostat |28 and its environment rises, the thermostat will exert a force to urge the lower end of valve |39 toward the outer edge of partition ||8 and it will be observed that when the thermostat |29 is in a position to bring the curved lower end of the valve |39 against the outer edge of the angular partition ||8, the valve |39 will provide a restriction to the flow of exhaust gases past the outer end of the partition H8, thereby causing a rise in the pressure of the exhaust gases in the heating channels upon the lower portion of valve |09 to overcome the eiect of weight I3 whereupon the valve |99 will be moved to a position to cut ofi the flow of exhaust gas to the chamber 5| and heating of the intake charge will cease.

Figure 6 also illustrates in detail the manner in which the channels 65 and 69 are curved up to the top of the chamber 5| to open into the fuel outlet passages of the dual carburetor 55. The upper portions of these channels are separated by a central partition |34 and from their upper ends, as illustrated in Figure 6, each of the channels 65 and 96 is curved downwardly and has a Cil downward inclination throughout its length so that any gasoline condensed in the channels will flow by gravity to the bottom of the distributing chambers 11 and 18. llhe channels 65 and 66 are also curved inwardly toward each other so that outside of the chamber 5| the axes of the two channels are substantially co-incident.

Referring now to Figure 7, it will be observed that in the broken away portion of the drawings, I have illustrated a crank shaft generally indicated at |46 connected with pistons, one of which is indicated at |42, by connecting rods as indicated at |43, in the conventional manner. The pistons are reciprocally mounted in cylinders as indicated at |135 which are cast in a cylinder block iii? and substantially completely surrounded by water jackets as indicated at |49. A cam shaft |55 is rotatably mounted in the cylinder block and operatively connected with the crank shaft by means of timing gears contained in the timing gear casing 6. The cam shaft |59 operates intake and exhaust valves as indicated at |52 and |53 respectively, and in combination with the crank shaft establishes the ring sequence of the engine cylinders. The exhaust and intake valves are provided with springs, guides, tappets and adjusting means in the conventional manner. The cylinder block |41 is further provided with apertures as indicated at 655 in Figure 6 to afford access to the valve adjusting means and these apertures are covered by plates as indicated at |56.

In an internal combustion engine constructed according to the idea of this invention, the crank shaft Mil and the cam shaft 56 are so constructed and so related as to provide for a ring sequence in the order 1, '1, 2, 6, 3, 10, 4, 9, 5, 8, or the reverse order, 1, 8, 5, 9, 4, 10, 3, 6, 2, '7, assuming that the cylinders of the engine are numbered consecutively from one end to the other and that the numbers indicating the above firing sequence are the numbers applied in consecutive order to the engine cylinders. It will be observed that this particular firing sequence gives a succession of power impulses which alternate between the forward and rearward halves of the engine and proceed in consecutive steps from the center toward each end thereof. As the firing order is definitely dependent on the form of the crank shaft, a further discussion thereof will be deferred until the construction of the crank shaft as illustrated in Figures 8, 9, 10, 11 and 12 hasbeen described.

A crank shaft involving to a considerable degree the principles and construction of the crank shaft forming an integral part of this invention has been previously described in the application of Delmar G. Roos, Serial No. 568,968, filed October l5, 1931. The present crank shaft, however, is regarded as an improvement upon the crank shaft illustrated and described in that prior application.

Referring to Figure 8, it will be observed that the crank shaft forming an integral part of this invention comprises ten connecting rod bearings, and six main bearings arranged in two similar but reversely positioned groups of ve connecting rod bearings and three main bearings in each group. Each group of five crank bearings is integrally balanced insofar as it is possible to balance a group of an odd number of crank bearings, the unbalanced forces remaining in each group are then counter-acted by the manner in which the two groups are related in the complete crank shaft. For the sake of convenience in description, the connecting rod bearings or crank bearings are numbered beginning at the front end of the crank shaft in consecutive order as C-I to C-I inclusive, and the main bearings are numbered beginning at the same end of the crank shaft as M-I to M-6 inclusive. As illustrated in Figure 9, the consecutive crank bearings in each half of the crank shaft are spaced at a rotational angle of two-fifths of a circle from each other, thus C--2 is two-fifths of a circle from C-|, and C-3 is two-fifths of a circle or 144 from C-2. C-5 and C-6, the adjacent end crank bearings of the two halves of the crank shaft, are arranged in co-axial position relative to each other and this arrangement causes the bearings C| and C-|0, C-4 and C-1, C-2 and C-9, and C-3 and C-8 to be positioned in co-aXial relation.

The first four bearings C-I, C-2, C-3 and C--4 and the last four C-1, C8, 0 9 and C-IU are arranged in pairs with a flying crank as indicated at |60, |6|, |62 and |63 between the two crank bearings of each pair. As the two crank bearings in each pair are spaced apart a rotational angle of 144, they are not directly opposite each other and hence each crank bearing does not simply balance out the rotational force of the opposite bearing but there is a rotational force on one side of the crank shaft contributed to by both bearing pins. In order to balance out this rotational force in each pair, a counter-weight portion is formed on each iiying crank as illustrated at 65 in Figure l1. This counter-weight portion is so proportioned that the combined centers of gravity of the two crank pins and the flying crank in each pair will lie on the axis of the crank shaft. It will now be observed from an inspection of Figure 9, that when the two pairs of crank bearings, C-I, C-2, C-3 and C-4, are placed together in assembled relation as illustrated in Figures 8 and 9 that this portion of the crank shaft is then out of balance in a manner which would give an unbalanced rocking or torsional Vibration to the crank shaft. This force is compensated by extending the crank throws between the main bearing M-I and the crank bearing C-I, and the main bearing M-3 and the crank bearing C-5 in the front half of the crank shaft, and the crank throws between the crank bearing C--G and the main bearing M-4 and the crank bearing C-I and the main bearing M-6 in the rear half of the crank shaft to form counterweights as illustrated in Figure l0. The crank throw |68 between the main bearing M-I and the crank bearing C-I is illustrated in elevation in Figure l0 and this figure clearly illustrates that the counterweight portion |69 is rotated at an angle ,6 from a position directly opposite the crank bearing C-I so that the combined centers of gravity of the counterweight portion and the crank bearing C-| will lie outside of the axis of the crank shaft. Referring to Figure 9, it will be observed that the counterweight portion |10 of the crank throw |12 between the main bearing M-3 and the crank bearing C- is rotated at an angle equal to from a position directly opposite the crank bearing C-S and that the counterweight portions |69 and |10 bear such angular relation to each other that a line joining the combined centers of gravity of the crank pin C-l and the counterweight |69 and the crank pin C-5 and the counterweight will pass at its center through the axis of the crank shaft. The same system of counterweighting is applied to the crank throws |14 and |15 in the rear half of the crank shaft. It will be apparent from the above description that the four front crank bearings and the four rear crank bearings are placed in perfect static and dynamic balance in each group. This construction then leaves the two center crank bearings C-E and C--6 and that portion |11 of the crank shaft which joins these two bearings entirely unbalanced. However, as the two crank bearings C-5 and C-6 and the portion |11 of the crank shaft which lies between these two bearings are all co-axial, the unbalanced effect of these crank bearings and the intermediate portion of the crank shaft can readily be counteracted by a simple counterweight |18 illustrated in elevation in Figure 12. This counterweight comprises a stem portion |19 and a weight portion |80, the weight portion being positioned directly opposite the crank bearings C-S and C-B and the end of the stem opposite the weight portion being formed integrally with the portion |11 of the crank shaft. This counterweight |18 is of such weight and shape as to bring the combined centers of gravity of the counterweight and the crank bearings C-5 and C-G and the intermediate portion |11 of the crank shaft to the axis of the crank shaft.

The crank shaft is provided at the rear end thereof with oil grooves |82 and a clutch flange |84 and at the front end thereof with a timing gear bearing |85 and fan belt pulley and vibration dampener bearing |86 and a threaded end portion |81 to receive the starting crank nut |8.

It will now be apparent that in an engine constructed as described above, the pistons in cylinders 1 and 10 connected to crank bearings C-I and C-IU will move together and will reach top dead-center simultaneously. Likewise the pistons in cylinders 3 and 8 will move together and will reach top dead-center simultaneously 72 of crank shaft rotation behind the top dead-center position of pistons 1 and 10. Pistons 5 and 6 will reach top dead-center together 72 behind pistons 3 and 8, pistons 2 and 9 will reach their top deadcenter position together 72 behind pistons 5 and 6 and pistons 4 and 7 will reach top dead-center '72 behind pistons 2 and 9. If we consider the position of the crank shaft in relation to the engine at which piston No. l is at top dead-center having just completed its compression stroke and being about to begin its power stroke, piston No. 10 at that time will be at the top of its exhaust stroke and about to begin its intake stroke. The next two pistons coming up to top dead-center are pistons 3 and 8. However, piston No. 3 is in the same half of the engine as piston No. l and as it is desirable to alternate ring strokes between the two halves of the engine, cylinder No. 8 will be the next cylinder to nre. Following cylinder No. 8, cylinder No. 5 in the opposite half of the engine from No. 8 will re, then cylinder 9 followed by cylinder 4 and the remaining cylinders will then re in the sequence 10, 3, 6, 2, '7. This firing order will be readily apparent from an observation of the positions of the consecutively numbered crank pins in Figure 9. This is the preferred firing order and is the firing order which would preferably be` applied to an engine in which the crank shaft is rotated in the clockwise direction in the conventional manner. It is quite possible, however, to construct an engine crank shaft would rotate in the anti-clockwise direction in which case the firing order would simply be the reverse of that stated above, namely, l, '7, 2, 6, 3, 10, 4, 9, 5, 8. With the preferred firing sequence described above it will now be apparent that as the crank bearings C-|, C-8 and C-S altogether describe an angle of less than which is the angle from top dead-center to bottom dead-center, this engine will have the distinct advantage that power from three cylinders will be continuously, overlappingly applied to the crank shaft, thereby giving an extremely smooth power flow from the engine. However, as three of the engine cylinders continuously overlap on the power stroke, it must naturally follow that three cylinders will continuously overlap on the intake stroke and from a careful observation of the firing sequence it will be observed that two adjacent cylinders in each half of the engine will be continuously overlapping on the intake stroke. When this condition occurs, that cylinder which begins its intake stroke rst has a tendency to rob fuel mixture from the subsequently intaking cylinder, thereby tending to cause uneven power strokes among the different cylinders of the engine. This condition, however, has been entirely obviated by the intake manifold as illustrated in Figures l, 2, 3 and 4 and described in detail above. This intake manifold besides assuring an independent and ample supply of explosive mixture tothe individual engine cylinders, at the same time provides for adequate heating of the intake mixture by heat transfer from the exhaust gases.

Due to the unusual length of the engine illustrated and described herein, I have found it desirable to form the cylinder head in two sections as indicated at 26 and 2| in Figure 1 and to supply an individual outlet for cooling fluids as indicated at 26 and 21 in each portion of the cylinder head. A 1

An aperture |88 has been provided between the two portions of the cylinder head for the extension therethrough of a commutator shaft adapted to actuate an ignition commutator, not illustrated. I have also found it desirable to reinforce the crank case of the engine by additional anges and ribs as indicated at |89 'and |90 in Figure 7. An oil pan |92 is Secured to the bottom of the crank case in the tonventional manner as by stud bolts |94 and is provided interiorly thereof with a drip pan |96.

While I have indicated in the above description that the crank shaft is statically and dynamically balanced as an integral unit, I have found it highly desirable in practice to actually over-balance the crank shaft in order to counterbalance the rotating mass of the connecting rods journaled on the crank shaft as well as to counterbalance the actual mass of the crank pinsv themselves. This construction is accomplished by simply temporarily adding to each crank pin a weight equal to the weight of the rotating mass of the connecting rod as indicated diagrammatically at |98 in Figure 13 and then accurately counter-balancing the crank shaft with the additional weights attached. It will be apparent that this construction necessitates the use of somewhat larger counter-weights than would be necessary if the weight of the crank pins alone were counter-balanced. f

An inspection of diagrammatic Figure 14 clearly illustrates the fact that by providing aV Vcrank shaft of the form illustrated and described above, the rocking couples in the engine'due to the inertia of the unbalanced rotating parts in each half of the engine are at all times equally spaced upon each side of the center of gravity of the engine and are of equal intensity, whereby the force exerted by the rocking couple upon one side of the center of gravity of the engine cancels out the force exerted by the rocking couple on the opposite side of the center of gravity of the engine and entirely obviates any tendency of the engine to move about its center of gravity.

A consideration of the above description taken with the accompanying drawings will now indicate that I have provided an in-line ten cylinder lengine having among others the following advantageous characteristics. In the rst place the explosive mixture fed to the cylinders is adequately heated to completely evaporate the fuel charge before the mixture enters the cylinders and the heating thereof is automatically controlled in accordance with the operating temperature and power output of the engine. Secondly, each cylinder has a separate and independent intake passage from the cylinder to one of the two distributing chambers positioned opposite each half of the engine, and the sequence of intake impulses occurs in such order that the fuel mixture flowing through the distributing chamber is given a definite rotary motion about the vertical axis of the chamber to create a more complete mixture of the fuel and air comprising the mixture, and to prevent stagnation of any part of the mixture with a consequent condensation of fuel. Thirdly, the firing sequence occurs in such order that the power strokes alternate between the two halves of the engine and occur at equally spaced intervals, so that the power of three of the ten cylinders is continuously overlappingly applied to the crank shaft of the engine. Fourth, the crank shaft is so arranged and so counterbalanced that the effect of both torsional and rocking forces are entirely eliminated. Fifth, the particular structure of the crank shaft illustrated and described above provides a crank shaft having ample strength and rigidity which at the same time requires only six main bearings to support the ten crank shaft bearings, thereby providing for an engine length with practical and useful limits, and also obviating the necessity of reducing the width of the main bearings to a point where such bearings would not be durable in use, and lastly the engine described above has the important characteristics of a rhythmic and uniform flow of power coupled with an absolute dynamic balance of vall moving parts which renders the engine smooth and quiet in operation to a superlative degree.

While I have illustrated and described a particular mechanical embodiment of the idea of the invention, it is to be understood that the invention is not limited to the specific device as illustrated and described but that such changes in the size, shape and arrangement of parts may be resorted to as come within the scope of the subjoined claims.

Having now described my invention so that others skilled in the art may clearly understand the same, what I desire to secure by Letters Patent is as follows:

1. A multi-cylinder four stroke cycle internal combustion engine having cylinders in line, a crank shaft having crank throws arranged in progressive spiral formation from the ends of Said shaft to the center thereof, pistons in said cylinders, connecting rods operatively connecting said pistons with said crank throws, intake and exhaust valves, appropriate intake and exhaust ports for said valves, an ignition system having a firing sequence such that a plurality Yof said engine cylinders .overlap on .their powerstrokes and adjacent engine cylinders overlap on their intake strokes, and an intake manifold having a central distributing chamber and independent conduits from said distributing chamber to each of said engine cylinders, said conduits surrounding said chamber in equally spaced relation to cause the fuel charge to have a rotary motion in said chamber.

2. In a four stroke cycle internal combustion engine having ten cylinders arranged in line and provided with suitable intake and exhaust ports, a piston in each cylinder, an engine crank shaft having ten throws angularly disposed from the ends of said shaft to the center thereof in such order that if the shaft be rotated the throws will pass through a radial plane including the shaft axis in the order 1-10-8 3-6-5-2-- 9-4-7, or the reverse according to the sense of rotation, reaching firing position in the order l-'7-2-6-3-10495-8 or the reverse; connecting rods operatively connecting the several pistons with the several crank bearings; an intake manifold having five delivery ports connected with a central distributing chamber in each half thereof, and communicating each with a single delivery port in the engine; vsaid delivery ports being arranged to cause the fuel charge to have a rotary motion in said chambers and to cause each cylinder to draw its firing charge directly from the associated central distributing chamber so that no two cylinders will draw mixture from the same delivery port of the intake manifold.

3. In an internal combustion engine having cylinders, pistons in said cylinders and suitable intake and exhaust ports connected with said cylinders, a balanced crank shaft, connecting rods operatively connecting said pistons with said crank shaft, said crank shaft having ten crank bearings no two of which in the same half of the crank shaft lie in the Vsame radial plane, said crank bearings being angularly disposed from the ends to the center of said crank shaft in such order that if the shaft be rotated no two longitudinally adjacent crank bearings will pass through a radial plane including the shaft axis in succession, means for conducting cornbustible mixture to the intake ports of said engine, said means comprising separated distributing chambers and separate branches surrounding said `chambers arranged to cause the fuel charge to have :a rotary motion'in said chambers and so thatno--two cylinders lfiring in succession draw mixture from the intake manifold adjacent to the same delivery port.

4. In an internal combustion engine of the four-cycle type having ten cylinders in line consecutively numbered 1 to 10, the combination of a crank shaft having crank pins arranged in independently balanced pairs and in two independently balanced 4groups of five consecutive crank pins, consecutive crank pins except the two center pins being spaced relative to each other at a rotational angle of two-fifths of a circle to provide for a firing sequence of Athe order 1 7- 2-6-3-10-49-58, and a manifold having a plurality of distributing chambers and separate branches leading therefrom to each cylinder arranged to cause the fuel charge to have a rotary motion as it enters each of said branches.

5. In an internal combustion engine of the four-cycle type having ten cylinders in line consecutively numbered 1 to 10, the combination of a crank shaft having crank pins arranged in independently balanced pairs and in two independently balanced groups of ve consecutive crank pins, consecutive crank pins except the two center pins being spaced relative to each other at a rotational angle of two fths of a circle to provide for a firing sequence of the order 1-8-5-9-4-10-3-6-2-7, and a manifold having a plurality of distributing chambers and separate branches leading to each of said cylinders arranged to cause the fuel charge to have a rotary motion as it enters each of said branches.

6. In an internal combustion engine of the four-cycle type having ten cylinders in line and a ring order of a sequence wherein at least two adjoining cylinders overlap on their intake periods, an intake manifold comprising a carbureterchamber, a plurality of distributing chambers, pneumatically connected with said carbureter chamber and a separate branch from said chambers to each cylinder, said branches being positioned in respect to said distributing chambers to cause the fuel charge to have a rotary motion as it passes through said distributing chambers.

7. In an internal combustion engine of the four-cycle type having ten cylinders in line and a firing order of a sequence wherein two or more cylinders in the same half of the engine overlap on their intake periods, an intake manifold therefor comprising, a separate distributing chamber for each half of the engine, and substantially equally spaced separate manifold branches surrounding the respective distributing chamber, and communicating with the engine cylinders whereby the fuel charge has a rotary motion as it passes through the distributing chamber.

8. In an internal combustion engine of the four-cycle type having ten cylinders in line and a firing sequence wherein two or more cylinders in the same half of the engine overlap on their intake periods, an intake manifold therefor comprising, a separate distributing chamber for each half of the engine, and a manifold portion interposed between each distributing chamber and the respective half of the engine, each of said manifold portions comprising ve branches leading directly from the respective distributing chamber to the five cylinders in the respective half of the engine so arranged in respect to the firing sequence of the engine as to give the fuel charge a rotary motion as it passes through the distributing chamber.

9. In an internal combustion engine of the four-cycle type having ten cylinders in line and a firing sequence wherein two or more cylinders in the same half of the engine overlap on their intake periods, an intake manifold therefor comprising, a carburetor chamber substantially centrally located with respect to said engine, a separate distributing chamber for each half of said engine, and a header leading from said carburetor chamber to each of said distributing chambers, each of said distributing chambers having branches so arranged in respect to the firing sequence of the engine as to give the fuel charge a rotary motion as it passes through the distributing chamber.

10. In a multi-cylinder internal combustion engine of the four-cycle type, an intake manifold comprising, a carburetor chamber, a distributing chamber pneumatically connected with said carburetor chamber, independent manifold branches separately connecting the individual engine cylinders with said distributing chamber, said manifold branches being so arranged with respect to the ring sequence of said engine that said cylinders draw their intake charges in succession substantially around the circumference of said distributing chamber, thereby giving to the fuel charge in said distributing chamber a rotary motion about a vertical axis.

DELMAR G. ROOS. 

